Currently, in an aircraft section including an undercarriage housing, the pressurized flooring includes a series of metallic beams arranged longitudinally in relation to the aircraft axis, and parallel to one another. Each beam includes an upper sole, intended to support the seat rails and a lower sole, intended to support the curved membranes that ensures cabin flooring tightness. A vertical web plate connects the upper sole to the lower sole. The lower sole is provided with two oblique feet arranged on each side of the vertical web plate and forming an inverted V in order to offer, for the face directed toward the upper sole, a support surface tangent to the curvature of the curved membranes.
In flight, the oblique feet of the lower sole are submitted to unfolding constraints. By unfolding constraint, one understand the forces having a tendency to flatten the beam, i.e. compression forces, forcing the oblique feet in the extension of the vertical web plate, and pull-out forces, tending to separate the feet away from one another, spreading them in a horizontal plane. The junction node between the two oblique feet and the vertical web plate is thus a particularly fragile zone of the beam for pressurized floor.
Currently, in aeronautics, one tries to use composite materials to manufacture all or portions of the parts entering in an aircraft manufacture, notably to decrease the overall mass of the aircraft. However, it is not currently possible to consider realizing such a beam for flooring pressurized in composite material, since such material is known to have less resistance to unfolding constraints.